kclient: trim caps on demand

diff --git a/src/include/ceph_fs.h b/src/include/ceph_fs.h
index 3bae80313c71051a5feef448af64f3932bd5ad8b..ac37686e2d5dc368c5bb2264622991f7107efabf 100644 (file)
--- a/src/include/ceph_fs.h
+++ b/src/include/ceph_fs.h
@@ -27,7 +27,7 @@
 #define CEPH_MDS_PROTOCOL     9 /* cluster internal */
 #define CEPH_MON_PROTOCOL     4 /* cluster internal */
 #define CEPH_OSDC_PROTOCOL   13 /* public/client */
-#define CEPH_MDSC_PROTOCOL   20 /* public/client */
+#define CEPH_MDSC_PROTOCOL   21 /* public/client */
 #define CEPH_MONC_PROTOCOL   12 /* public/client */
 
 
@@ -394,6 +394,7 @@ enum {
        CEPH_SESSION_REQUEST_RENEWCAPS,
        CEPH_SESSION_RENEWCAPS,
        CEPH_SESSION_STALE,
+       CEPH_SESSION_TRIMCAPS,
 };
 
 static inline const char *ceph_session_op_name(int op)
@@ -406,6 +407,7 @@ static inline const char *ceph_session_op_name(int op)
        case CEPH_SESSION_REQUEST_RENEWCAPS: return "request_renewcaps";
        case CEPH_SESSION_RENEWCAPS: return "renewcaps";
        case CEPH_SESSION_STALE: return "stale";
+       case CEPH_SESSION_TRIMCAPS: return "trimcaps";
        default: return "???";
        }
 }
@@ -414,6 +416,7 @@ struct ceph_mds_session_head {
        __le32 op;
        __le64 seq;
        struct ceph_timespec stamp;
+       __le32 max_caps;
 } __attribute__ ((packed));
 
 /* client_request */

diff --git a/src/kernel/caps.c b/src/kernel/caps.c
index 53f8faf9338f5b0cc6a4f7613fd60ac1db92d20b..a755c95c5f612581a26d796f9260b26899dbc6a1 100644 (file)
--- a/src/kernel/caps.c
+++ b/src/kernel/caps.c
@@ -605,6 +605,23 @@ int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented)
        return have;
 }
 
+int __ceph_caps_issued_other(struct ceph_inode_info *ci, struct ceph_cap *ocap)
+{
+       int have = ci->i_snap_caps;
+       struct ceph_cap *cap;
+       struct rb_node *p;
+
+       for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
+               cap = rb_entry(p, struct ceph_cap, ci_node);
+               if (cap == ocap)
+                       continue;
+               if (!__cap_is_valid(cap))
+                       continue;
+               have |= cap->issued;
+       }
+       return have;
+}
+
 static void __touch_cap(struct ceph_cap *cap)
 {
        struct ceph_mds_session *s = cap->session;

diff --git a/src/kernel/mds_client.c b/src/kernel/mds_client.c
index 0a047c3fd82e1e04348cf033805a5cae6f421ddd..1534c1b6e07686a74b7074be818c0830aa68fedb 100644 (file)
--- a/src/kernel/mds_client.c
+++ b/src/kernel/mds_client.c
@@ -300,6 +300,7 @@ static struct ceph_mds_session *register_session(struct ceph_mds_client *mdsc,
        s->s_renew_requested = 0;
        INIT_LIST_HEAD(&s->s_caps);
        s->s_nr_caps = 0;
+       s->s_max_caps = 0;
        atomic_set(&s->s_ref, 1);
        INIT_LIST_HEAD(&s->s_waiting);
        INIT_LIST_HEAD(&s->s_unsafe);
@@ -793,6 +794,52 @@ static int __close_session(struct ceph_mds_client *mdsc,
        return request_close_session(mdsc, session);
 }
 
+/*
+ * Trim old(er) caps.
+ */
+static int trim_caps_cb(struct inode *inode, struct ceph_cap *cap, void *arg)
+{
+       struct ceph_mds_session *session = arg;
+       struct ceph_inode_info *ci = ceph_inode(inode);
+       int used, oissued, mine;
+
+       if (session->s_nr_caps <= session->s_max_caps)
+               return -1;
+
+       spin_lock(&inode->i_lock);
+       mine = cap->issued | cap->implemented;
+       used = __ceph_caps_used(ci);
+       oissued = __ceph_caps_issued_other(ci, cap);
+
+       dout(20, "trim_caps_cb %p cap %p mine %s oissued %s used %s\n",
+            inode, cap, ceph_cap_string(mine), ceph_cap_string(oissued),
+            ceph_cap_string(used));
+       if ((used & ~oissued) & mine)
+               goto out;   /* we need these caps */
+
+       /* try to drop referring dentries */
+       d_prune_aliases(inode);
+       dout(20, "trim_caps_cb %p cap %p  pruned, count now %d\n",
+            inode, cap, atomic_read(&inode->i_count));
+
+out:
+       spin_unlock(&inode->i_lock);
+       return 0;
+}
+
+static int trim_caps(struct ceph_mds_client *mdsc,
+                    struct ceph_mds_session *session,
+                    int max_caps)
+{
+       dout(10, "trim_caps mds%d start: %d / %d caps\n", session->s_mds,
+            session->s_nr_caps, max_caps);
+       session->s_max_caps = max_caps;
+       iterate_session_caps(session, trim_caps_cb, session);
+       dout(10, "trim_caps mds%d done: %d / %d caps\n", session->s_mds,
+            session->s_nr_caps, max_caps);
+       return 0;
+}
+
 /*
  * Allocate cap_release messages.  If there is a partially full message
  * in the queue, try to allocate enough to cover it's remainder, so that
@@ -1724,6 +1771,10 @@ void ceph_mdsc_handle_session(struct ceph_mds_client *mdsc,
                send_renew_caps(mdsc, session);
                break;
 
+       case CEPH_SESSION_TRIMCAPS:
+               trim_caps(mdsc, session, le32_to_cpu(h->max_caps));
+               break;
+
        default:
                derr(0, "bad session op %d from mds%d\n", op, mds);
                WARN_ON(1);

diff --git a/src/kernel/mds_client.h b/src/kernel/mds_client.h
index 8a889f58554213eddcee3bcd2b8f1f756319d1a8..2bf5dc8cae81ab085e37fb69659c07dd5835c746 100644 (file)
--- a/src/kernel/mds_client.h
+++ b/src/kernel/mds_client.h
@@ -120,7 +120,7 @@ struct ceph_mds_session {
        unsigned long     s_cap_ttl;  /* when session caps expire */
        unsigned long     s_renew_requested; /* last time we sent a renew req */
        struct list_head  s_caps;     /* all caps issued by this session */
-       int               s_nr_caps;
+       int               s_nr_caps, s_max_caps;
        atomic_t          s_ref;
        struct list_head  s_waiting;  /* waiting requests */
        struct list_head  s_unsafe;   /* unsafe requests */

diff --git a/src/kernel/super.h b/src/kernel/super.h
index 4c30fade0b1dfba62feefd1625bdc5414d2b6e18..bb41d3cdfaf654f599773ede885cf06329b8704d 100644 (file)
--- a/src/kernel/super.h
+++ b/src/kernel/super.h
@@ -506,6 +506,8 @@ static inline bool __ceph_is_any_real_caps(struct ceph_inode_info *ci)
 
 extern int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented);
 extern int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int t);
+extern int __ceph_caps_issued_other(struct ceph_inode_info *ci,
+                                   struct ceph_cap *cap);
 
 static inline int ceph_caps_issued(struct ceph_inode_info *ci)
 {

diff --git a/src/messages/MClientSession.h b/src/messages/MClientSession.h
index f7799ac9edec78a5b1840744261b322f0d50d819..e472870e5bab055bee09817f69958b4ee1e7f41a 100644 (file)
--- a/src/messages/MClientSession.h
+++ b/src/messages/MClientSession.h
@@ -23,19 +23,22 @@ public:
   int32_t op;
   version_t seq;  // used when requesting close, declaring stale
   utime_t stamp;
+  int32_t max_caps;
 
   MClientSession() : Message(CEPH_MSG_CLIENT_SESSION) { }
   MClientSession(int o, version_t s=0) : 
     Message(CEPH_MSG_CLIENT_SESSION),
-    op(o), seq(s) { }
+    op(o), seq(s), max_caps(0) { }
   MClientSession(int o, utime_t st) : 
     Message(CEPH_MSG_CLIENT_SESSION),
-    op(o), seq(0), stamp(st) { }
+    op(o), seq(0), stamp(st), max_caps(0) { }
 
   const char *get_type_name() { return "client_session"; }
   void print(ostream& out) {
     out << "client_session(" << ceph_session_op_name(op);
     if (seq) out << " seq " << seq;
+    if (op == CEPH_SESSION_TRIMCAPS)
+      out << " max_caps " << max_caps;
     out << ")";
   }
 
@@ -44,11 +47,13 @@ public:
     ::decode(op, p);
     ::decode(seq, p);
     ::decode(stamp, p);
+    ::decode(max_caps, p);
   }
   void encode_payload() { 
     ::encode(op, payload);
     ::encode(seq, payload);
     ::encode(stamp, payload);
+    ::encode(max_caps, payload);
   }
 };